Plenty of people have now heard about Leah Libresco, an atheist blogger who recently converted to Christianity. The ostensible reason for the conversion was her nagging moral commitments that she finally decided made better sense on a theistic than atheistic worldview. In contrast with Libresco is Joel Marks, a Kantian-ethicist-turned-moral-antirealist. He used to be a firm believer in moral truths, and, like Libresco, he used to think that an atheistic picture of reality is adequate to undergird such facts. He was quite sure about the wrongness of torturing animals or massacring innocents. They were, as he put it in an op-ed piece from August 2011 in The New York Times, “wrong, wrong, wrong.” Not anymore. He came to think that such moral convictions are mere preferences. Whereas he had been sure of their wrongness, suddenly he knew it no more. “I was not merely skeptical or agnostic about it; I had come to believe, and do still, that these things are not wrong.” Marks didn’t run out to engage in such practices; he simply came to think that the whole category of morality is misguided. What drives human actions anyway, he writes, is desire; and his desires subsequent to what he dubbed his anti-epiphany didn’t much change. So he still strives to make the world more to his liking—a world of less brutality and more compassion—but he doesn’t think morality has anything to do with it. He tries to educate people about facts of suffering and exploitation and abuse in an effort naturally to elicit within them a desire to see and effect change, and he thinks the liberation from conducting such discourse with moral terminology is actually helpful.

Marks had earlier rejected the view that morality could find its foundation in God on the basis of the Euthyphro Dilemma. The famous Dilemma traces to an early Socratic dialogue, and today we would express the challenge it poses like this: Is something moral because God commands it, or does God command it because it is moral? If the former, morality seems arbitrary; if the latter, God seems irrelevant to morality. Although commonly repeated by ethicists, this objection to religious ethics has been thoroughly discredited. In our recent book, Jerry Walls and I made such a case, as have numerous others. Setting that objection aside, Libresco and Marks both found themselves with this insight: an atheistic world can’t make morality anything more than sentiment and preference. At present this view remains a minority view among most secularists, but it’s increasingly common; Nietzsche predicted that the implications of the death of God would take a few generations. They then found themselves with this further question: What then do we do with our moral convictions? Libresco took her nonnegotiable and inviolable convictions as serious evidence that the world isn’t atheistic; Marks in diametric opposition bit the bullet and gave morality up.

Both Marks and Libresco were basing their thinking on this sort of insight, which we can call their “shared premise”: If there’s no God, then there’s no morality. But then their ways parted. Libresco added this additional proposition: There is morality—binding, authoritative, objective morality. Therefore (by what philosophers call modus tollens), God exists. Marks in contrast added to their shared premise this premise: There’s no God. And (by what philosophers call modus ponens) he concluded that there is no morality.

Both arguments are logically impeccable in terms of their structure. The question boils down to which of the following claims is more obvious: that there is binding, authoritative, objective morality, or that God does not exist. Plenty of analysts, theists and atheists alike, readily affirm that most people can clearly apprehend moral facts of which we can be quite sure—torturing children for fun is wrong, mocking homosexuals is cruel and bad, and the like—so rejecting such a proposition strikes most people as wrong. In fact, such truths may be more obvious than God’s existence; but that doesn’t mean that God isn’t needed as the foundation of such truths. (To think otherwise confuses what philosophers call ontology and epistemology.) The question here is whether the alleged fact of God’s not existing is more obvious than the affirmation of moral facts. I see no compelling reason to think so, and have not heard any reasons to think so; in fact, the obvious nature of moral facts bolsters my belief that faith in God as the best explanation of such facts is eminently logical. So by my lights, Libresco’s response to the premise she shares with Marks seems the more rational way to go.

With his co-author, Jerry Walls, Dr. Baggett authoredGood God: The Theistic Foundations of Morality. The book won Christianity Today’s 2012 apologetics book of the year of the award. He recently published a sequel with Walls that critiques naturalistic ethics, God and Cosmos: Moral Truth and Human Meaning. They are under contract with Oxford University Press for a third book in the series, a book that will chronicle the history of moral arguments for God’s existence. Dr. Baggett has also co-edited a collection of essays exploring the philosophy of C.S. Lewis, and edited the third debate between Gary Habermas and Antony Flew on the resurrection of Jesus. Dr. Baggett currently is a professor at the Rawlings School of Divinity in Lynchburg, VA.